CVE intelligence and bounded remediation

CVE-2022-20679 — Cisco Ios Xe security vulnerability

High CVSS 7.7

A vulnerability in the IPSec decryption routine of Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause an affected device to reload, resulting in a denial of service (DoS) condition. This vulnerability is due to buffer exhaustion that occurs while traffic on a configured IPsec tunnel is being processed. An attacker could exploit this vulnerability by sending traffic to an affected device that has a maximum transmission unit (MTU) of 1800 bytes or greater. A successful exploit could allow the attacker to cause the device to reload. To exploit this vulnerability, the attacker may need access to the trusted network where the affected device is in order to send specific packets to be processed by the device. All network devices between the attacker and the affected device must support an MTU of 1800 bytes or greater. This access requirement could limit the possibility of a successful exploit.

Severity
High
CVSS
7.7 (3.1)
Published
2022-04-15
CISA KEV
Not currently listed
Ecosystem
operating-system
Weaknesses
CWE-20

Affected products

  • cisco / ios_xe / 3.15.1xbs
  • cisco / ios_xe / 3.15.2xbs
  • cisco / ios_xe / 16.8.1
  • cisco / ios_xe / 16.8.1a
  • cisco / ios_xe / 16.8.1b
  • cisco / ios_xe / 16.8.1c

Showing 6 representative product identities from 109 source matches. Confirm exact affected versions with the linked vendor and NVD evidence.

Matched remediation archetype

Resource exhaustion and denial of service

This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.

Check exposure

  • Identify attacker-influenced work factors including input size, nesting, compression, fan-out, regex cost, allocation, recursion, retries, and connection lifetime.
  • Map per-request and shared CPU, memory, disk, descriptor, thread, queue, and downstream-service limits.
  • Determine whether authentication, tenancy, quotas, and rate controls apply before expensive processing begins.

Remediate safely

  • Bound input size, nesting, expansion, work, concurrency, queue depth, retries, and execution time before resource-intensive processing.
  • Release resources on every success, error, cancellation, and timeout path and use backpressure instead of unbounded buffering.
  • Update affected components and add small deterministic tests that assert resource ceilings rather than exhausting a host.

Authoritative sources

Complete CVE record and remediation plan

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